Paul Mero delves into due process, equal protection, and substance in the second part of an essay that lays out what state attorneys should have argued in the Kitchen v. Herbert case (which resulted in the overturning of Utah’s marriage law):

The “substance” in substantive due process has to mean something. The Court may not reasonably ignore original intent and embrace substantive due process only to ignore the substance that gives life, liberty and property meaning. For instance, if the Court determines that equal protection means only “equal” without examining what is being “protected,” it would miss the entire meaning of substance within the context of the 14th Amendment.

As the state already expressed, the burden of proof in the merits of this case are on the plaintiffs to show that same-sex marriage is in the state interest and serves the common good – not a burden to show that the 14th Amendment has new meaning and that same-sex marriage conforms to that new meaning. Voters overwhelmingly approved Utah’s marriage law. It was approved in the state interest and for the common good. The state interest, your Honor, not any other reason, was and remains at the heart of Utah’s marriage law – an important point proven by rational means.